so > [so greatly]
2 That he would algates with Pyrochles fight,
algates > anyhow, by any means
3 And his redeemer challenged for his foe,
challenged for > demanded as, laid claim to as
4 Because he had not well maintained his right,
maintained > defended
5 But yielded had to that same stranger knight:
stranger > foreign; new-come
6 Now gan Pyrochles wax as wood as he,